My son is 2. 5 months old, his birthweight (born on 5 Feb 2017) was 2. 6 kg. His current weight is 4 kg. From past 2 weeks he is passing motion for 2 to 3 times with yellow curdy and mucus filled poop. Is it normal to poop mucus? and has it any influence with weight gain? he is given only breast milk.